In recent years, digital signage technologies have been widely used that takes out an advertisement by delivering and reproducing signage content such as a commercial image to a display device, such as a liquid crystal display device, which is installed in event facilities, such as a soccer stadium, a baseball stadium, and a concert hall, commercial facilities, such as a shopping center, a hotel, a movie theater, and an amusement park, public transportation facilities, such as a station and an airport, and the like. The digital signage technology has an advantage in that because signage content is delivered with download delivery or streaming delivery via a network, a change of content can be made in a quick and easy manner. Furthermore, accordingly, the digital signage technology also has an advantage in that advertising can be performed in a more effective or efficient manner when compared with the case of a television CM, an advertisement poster, an advertising board, or the like.
As this digital signage technology, a technology is known that streaming-delivers streaming content from a moving image server to a set-top box and that, for display, outputs the streaming content, which is cached in a storage unit of the set-top box, to a display that is connected to the set-top box (PTL 1). The technology that is disclosed in PTL 1, for example, caches moving image data (the streaming content) in the storage unit at midnight, and thus can provide a stable service that does not depend on a band for a moving image server or a status of a network.